EP1310520A1 - Blowing agent composition for the production of foamed thermoplastic synthetic materials - Google Patents

Abstract

Foamed, thermoplastic polymers are prepared using a propellant composition comprising pentafluoropropane and/or pentafluorobutane and at least a further propellant. <??>A process for the production of foamed thermoplastic polymers (I) by foaming of a thermoplastic polymer using a propellant composition (II) is claimed. The propellant (II) comprises: <??>(A) pentafluoropropane, preferably 1,1,1,3,3-pentafluoropropane (HFC-245 fa) and/or pentafluorobutane, preferably 1,1,1,3,3-pentafluorobutane (HFC-365 mfc) and <??>(B) at least a further propellant consisting of low boiling , optionally halogenated hydrocarbons, ethers and halogenated ethers, difluoroethane (HFC-32), difluoroethane, preferably 1,1-difluoroethane (HFC-152a), 1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoropropane, preferably 1,1,1,3,3-pentafluoropropane (HFC-245 fa), hexafluoropropane, preferably 1,1,2,3,3,3-hexafluoro-propane (HFC-245a), hexafluoropropane, preferably 1,1,2,3,3,3-hexafluoropropane (HFC-236ea), 1,1,1,3,3,3-hexafluoropropane (HFC-236a) and/or heptafluoropropane, preferably 1,1,1,2,3,3,3-heptafluoropropane(HFC-227ea). <??>Independent claims are included for: <??>(i) the propellant composition (II) and <??>(ii) a closed cell, thermoplastic foam, preferably of polystyrene, polyethylene, polypropylene, PVC or PET, preferably polystyrene, prepared by the process and containing (II) in the closed cells.

Description

The invention relates to a process for the production of rigid polyurethane foams and foamed thermoplastics.

Polyurethane foams are used as heat- or sound-absorbing building materials. The production of single-component and multicomponent polyurethane foams with blowing agents based on liquefied CO ₂ is disclosed in WO 96/14354.

Foamed thermoplastics can, for example in the form of Plates are used as a heat or noise insulating component. The USA No. 5,276,063 discloses a process for producing extruded, closed-cell alkenyl aromatic Polymers using a blowing agent mixture which is 1,1-difluoroethane and another propellant with lower vapor pressure and even higher Solubility in the molten polymer. Suitable alkenyl aromatic polymers are, for example, polymers of styrene, alpha-methylstyrene, ethylstyrene, vinylbenzene, Vinyl toluene, chlorostyrene and bromostyrene. If desired, these polymers can be used Copolymers such as acrylic acid, acrylonitrile or butadiene. US-A 5,204,169 discloses the production of foamed thermoplastic polymers such as polystyrene using polyfluorinated hydrocarbons having 2 C atoms. The foamed Material is particularly suitable for food packaging. EP-A-0 436 847 discloses the production of foamed thermoplastic moldings Base of polyphenylene ether resins. As blowing agent hydrocarbons are recommended. Also useful are halogenated hydrocarbons having 1 or 2 carbon atoms mentioned.

The object of the present invention is a process for the production of rigid polyurethane foams by means of a selected, novel, advantageous blowing agent specify. Object of the present invention is also a method for Production of foamed thermoplastics by means of a novel, indicate advantageous propellant. These tasks are governed by the procedure and dissolved the blowing agent of the present invention.

The starting point was the surprising finding that pentafluorobutane, especially 1,1,1,3,3-pentafluorobutane (HFC-365mfc) in admixture with certain others Blowing agents one for the production of rigid polyurethane foams and foamed thermoplastic materials very well suitable composition provides.

The process according to the invention for the production of rigid polyurethane foams and foamed thermoplastics using a propellant sees in that the blowing agent used is a composition which comprises a) pentafluorobutane, preferably 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and b) at least one other Blowing agent selected from the group comprising low-boiling, aliphatic hydrocarbons, Ethers and haloethers; Difluoromethane (HFC-32); Difluoroethane, preferably 1,1-difluoroethane (HFC-152a); 1,1,2,2-tetrafluoroethane (HFC-134); 1,1,1,2-tetrafluoroethane (HFC-134a); Pentafluoropropane, preferably 1,1,1,3,3-pentafluoropropane (HFC-245fa); Hexafluoropropane, preferably 1,1,2,3,3,3-hexafluoropropane (HFC-236ea) or 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); and heptafluoropropane, preferably 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) or consists thereof.

According to one embodiment, a blowing agent is used which comprises 1,1,1,3,3-pentafluorobutane, 1,1,1,3,3-pentafluoropropane and at least one of the mentioned under b) Having propellant.

Preference is given to the embodiment which comprises 1,1,1,3,3-pentafluorobutane as under a) having said component.

The inventive method therefore preferably provides that as Propellant used a composition containing 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and at least one further blowing agent selected from the group comprising low boiling aliphatic hydrocarbons, ethers and haloethers; difluoromethane (HFC-32); Difluoroethane, preferably 1,1-difluoroethane (HFC-152a); 1,1,2,2-tetrafluoroethane (HFC-134); 1,1,1,2-tetrafluoroethane (HFC-134a); Pentafluoropropane, preferably 1,1,1,3,3-pentafluoropropane (HFC-245fa); Hexafluoropropane, preferably 1,1,2,3,3,3-hexafluoropropane (HFC-236ea) or 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); and heptafluoropropane, preferably 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) or consists of.

The term "low boiling hydrocarbons, ethers and halo ethers" means Compounds with a boiling point below 70 ° C, preferably below 55 ° C. Suitable hydrocarbons are those having 2 to 6 carbon atoms, for. Ethane, propane, Butane, pentane and hexane and mixtures thereof. This can be isomerically pure compounds or mixtures of different isomers are used. Under "butane" are understood mixtures of n-butane and i-butane. Such mixtures are commercially available. Pure n-butane or i-butane or their mixture in any composition is also usable, but very expensive. The same applies to higher homologues such as pentane etc.

The blowing agent compositions preferably contain 5 to 95% by weight. 1,1,1,3,3-pentafluorobutane, in particular 10 to 70 wt .-%.

Propellant compositions which, in addition to HFC-365mfc and one or more of the blowing agents listed above under b), such as hydrofluorocarbons or hydrocarbons, also contain liquefied carbon dioxide are also suitable for use in the process according to the invention. Preferably, then 2 to 50 wt .-% of CO _{2 are included} in the blowing agent composition. In addition, the propellant composition may still contain up to 30% by weight of additives which modify the properties of the plastic to be produced.

• HFC-365mfc und HFC-152a (70:30);
• HFC-365mfc und HFC-32 (70:30);
• HFC-365mfc, HFC-152a und CO₂ (60:30:10);
• HFC-365mfc, HFC-32 und CO₂ (60:30:10);
• HFC-365mfc, HFC-152a und Butan (60:30:10);
• HFC-365mfc, HFC-32 und Butan (60:30:10);
• HFC-365mfc, HFC-152a und HFC-134a (60:25:15);
• HFC-365mfc, HFC-32 und HFC-134a (60:25:15);
• HFC-365mfc und Dimethylether (80:20);
• HFC-365mfc und Pentan (50:50);
• HFC-365mfc und Propan (70:30);
• HFC-365mfc und Ethan (90:10);
• HFC-365mfc, Pentan und CO₂ (45:45:10);
• HFC-365mfc, Butan und CO₂ (50:40:10);
• HFC-365mfc, Propan und CO₂ (70:20:10);
• HFC-365mfc, Ethan und CO₂ (90:5:5).

Very suitable as blowing agents are, for. For example, the following compositions which may contain or consist of (examples of compositions indicating the parts by weight in parentheses):

• HFC-365mfc and HFC-152a (70:30);
• HFC-365mfc and HFC-32 (70:30);
• HFC-365mfc, HFC-152a and CO ₂ (60:30:10);
• HFC-365mfc, HFC-32 and CO ₂ (60:30:10);
• HFC-365mfc, HFC-152a and butane (60:30:10);
• HFC-365mfc, HFC-32 and butane (60:30:10);
• HFC-365mfc, HFC-152a and HFC-134a (60:25:15);
• HFC-365mfc, HFC-32 and HFC-134a (60:25:15);
• HFC-365mfc and dimethyl ether (80:20);
• HFC-365mfc and pentane (50:50);
• HFC-365mfc and propane (70:30);
• HFC-365mfc and Ethan (90:10);
• HFC-365mfc, pentane and CO ₂ (45:45:10);
• HFC-365mfc, butane and CO ₂ (50:40:10);
• HFC-365mfc, propane and CO ₂ (70:20:10);
• HFC-365mfc, ethane and CO ₂ (90: 5: 5).

Preferred blowing agent compositions contain 1,1,1,3,3-pentafluorobutane and difluoromethane and / or 1,1-difluoroethane, or consist of these compounds. Very particular use is made of compositions which contain 10 to 70% by weight of the HFC-365mfc and 90 to 30 wt .-% of HFC-152a and / or HFC-32 or from it consist.

In the following, the production of PU rigid foams will be further explained.

Examples of outstandingly useful flame retardants include reactive flame retardants such as brominated polyols. Also suitable are flame retardants based on organic phosphorus compounds, for example phosphate esters and phosphonic esters. These have organic groups, which also by a or more halogen atoms may be substituted. The organic groups can have aliphatic or aromatic character. Very suitable are phosphate esters and phosphonate esters formed by three C1-C6 alkyl groups containing one or two halogen atoms may be substituted, for example trischloroisopropyl phosphate, Trischloroethyl phosphate, trischloropropyl phosphate, dimethyl ethyl phosphate, tris dichloroisopropyl phosphate, Dimethyl methyl phosphonate, preferably trischloropropyl phosphate.

One embodiment of the process according to the invention for the production of rigid polyurethane foams provides that, provided that a) HFC-365mfc and b) 1,1,1,2-tetrafluoroethane (HFC-134a); 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); or 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) but containing no CO ₂ , low boiling, optionally halogenated hydrocarbons, ethers or halogenated ethers, the propellant composition is less than 50% by weight 1,1,1,3,3-pentafluorobutane and more than 50% by weight of 1,1,1,2-tetrafluoroethane; 1,1,1,3,3-pentafluoropropane; Contains 1,1,1,3,3,3-hexafluoropropane or 1,1,1,2,3,3,3-heptafluoropropane or consists thereof.

The effective amount of blowing agent composition which is obtained in the invention Procedure can be determined by simple hand tests. Advantageous the propellant composition is added in an amount of 1 to 50% by weight based on the total mixture of plastic to be foamed or the precursors (polyol, Isocyanate, adjuvant) and blowing agent composition.

Another object of the invention are substantially closed-cell Rigid polyurethane foams obtained by a content of the process according to the invention to be applied in the cells.

The production of such foams and the base materials that can be used for this purpose and the type of foam production are described in the European patent application EP-A-0 381 986; in "Ullmann's Encyclopedia of Industrial Chemistry", 5th Edition, Vol A21, pages 665-680; International Patent Applications WO 92/00345, 96/30439, 96/14354 and German Offenlegungsschrift DE 44 22 714 A1. You bet Polyisocyanates, for example, with 2 to 4 isocyanate groups.

They have an aliphatic hydrocarbon radical with up to 18 C atoms, a cycloaliphatic hydrocarbon radical with up to 15 C atoms, an aromatic Hydrocarbon radical having 6 to 15 carbon atoms or an aliphatic hydrocarbon radical with 8 to 15 C atoms on. Technically particularly preferred starting components For example, diphenylmethane diisocyanate, polymethylene polyphenyl isocyanate and their mixtures. It is also possible to use so-called "modified polyisocyanates" which carbodiimide groups, urethane groups, allophanate groups, isocyanurate groups, Contain urea groups or biuret groups.

Other starting components are compounds with at least 2 to isocyanates reactive hydrogen atoms. These are in particular compounds having a molecular weight of 400 to 10,000, preferably 2 to 8 Have hydroxyl groups and also amino groups, thiol groups or carboxyl groups can have.

If necessary, other auxiliaries and additives can be used. For example In addition, you can add chemical blowing agents such as water or other easily Use volatile organic substances as a physical blowing agent. Can be used also catalysts such as, for example, tertiary amines, such as dimethylcyclohexylamine, and / or organic metal compounds. It can be surface-active additives such as Emulsifiers or foam stabilizers, for example siloxane polyether copolymers, Reaction retarders, cell regulators such as paraffins, fatty alcohols or dimethylpolysiloxanes, Pigments, dyes, flame retardants such as phosphate esters or phosphonate esters, such as For example, trischloro-propyl phosphate can be used. Can still be used Stabilizers against aging and weathering, plasticizers, fillers, dyes, Antistatic agents, nucleating agents, pore regulators or biocidally effective Agents.

Well suitable catalysts are, for example, in the international patent application Called WO 96/14354. These include organic amines, amino alcohols and amino ethers such as morpholine compounds, for example dimethylcyclohexylamine, diethanolamine, 2-dimethylaminoethyl-3-dimethylaminopropyl ether, 2-dimethylaminoethyl ether, 2,2-dimorpholinodiethyl ether, N, N-dimethylaminoethylmorpholine, N-dimethylmorpholine. Also organometallic compounds such as tin, cobalt or iron compounds are useful as a catalyst. Tin dioctoate, cobalt naphthenate, for example, can be used. Dibutyltin dilaurate and iron acetonylacetate.

The propellants may contain adjuvants and additives such as water, one or more Catalysts, flame retardants, emulsifiers, foam stabilizers, binders, Crosslinking agents, UV stabilizers, nucleating agents and optionally further propellants. The propellant may, for. As the propolymers of polyol and polyisocyanate or diisocyanate be added, which is then foamed.

An advantage of the method according to the invention is first that the applied Propellant composition, which also belongs to the invention, favorable properties in terms of ODP, GWP and Photosmog owns. Compared with rigid polyurethane foams, made with pure hydrocarbons as blowing agent are, the foams produced by the process according to the invention are characterized by a better thermal conductivity.

A particular advantage of the polyurethane rigid foams obtainable by the process according to the invention comes at lower temperatures, mostly below about 15 ° C, to bear. Surprisingly, those according to the invention Process available polyurethane rigid foam not only a cheaper Thermal conductivity (i.e., the heat transfer is lower) than foams made from pure Hydrocarbons were produced, but even compared to foams, the with pure pentafluorobutane (HFC-365mfc) is the thermal conductivity lower. In largely closed-cell polyurethane rigid foams, which with Propellant mixtures which pentafluorobutane, preferably 1,1,1,3,3-pentafluorobutane and at least 1 of the above-mentioned further blowing agents, makes up in terms of thermal conductivity, d. H. the thermal insulation ability is more synergistic Effect of the blowing agent mixtures used noticeable. The using of Pentafluorobutane, preferably HFC-365mfc and at least one other of the above polyurethane foams obtainable with the stated blowing agents are suitable As a result, available polyurethane rigid foams are particularly well suited for Insulation against cold in a temperature range below about 15 ° C.

The production of thermoplastic foams will be further explained below.

With the method according to the invention, for example, in the above mentioned US patents 5,204,169 and 5,276,063 mentioned thermoplastics based on polymeric alkenylaromatics and those mentioned in EP-A-0 436 847 thermoplastic, based on polyphenylene ether compounds Plastic foams. Also foamable are thermoplastics based on of polyethylene, polyvinyl chloride (PVC) and polyethylene terephthalate (PET) and polypropylene. Particular preference is given to foaming in the process according to the invention Thermoplastic plastics based on polystyrene, polyethylene and polypropylene on. It is very particularly preferred, as thermoplastic polystyrene use.

An embodiment of the process according to the invention for producing plastics based on polystyrene or polyethylene provides that, provided that a) HFC-365mfc and b) 1,1,1,2-tetrafluoroethane (HFC-134a); 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); or 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) but containing no CO ₂ , the propellant composition is less than 50% by weight of 1,1,1,3,3-pentafluorobutane and more than 50% by weight of 1,1,1,2-tetrafluoroethane; 1,1,1,3,3-pentafluoropropane; Contains 1,1,1,3,3,3-hexafluoropropane or 1,1,1,2,3,3,3-heptafluoropropane or consists thereof. The same proviso also applies to this embodiment, provided that no further blowing agent from the group of low-boiling, optionally halogenated hydrocarbons, chlorine and halogen ethers is contained. With regard to preferred blowing agents, the statements made above for PU foams apply.

Advantageously, the blowing agent composition is used in an amount of from 1 to 30% by weight, based on the total mixture of thermoplastic material to be foamed and propellant composition.

A further subject of the present invention is a propellant composition, which can be used in the process according to the invention. It contains or consists of a) pentafluorobutane, preferably 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and b) at least one further blowing agent selected from the group comprising low-boiling aliphatic hydrocarbons, ethers and halogen ethers; difluoromethane (HFC-32); Difluoroethane, preferably 1,1-difluoroethane (HFC-152a); Pentafluoropropane preferably 1,1,1,3,3-pentafluoropropane (HFC-245fa); hexafluoropropane, preferably 1,1,2,3,3,3-hexafluoropropane (HFC-236ea) or 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); and heptafluoropropane, preferably 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea). A preferred composition contains or consists of: a) 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and b) at least one further blowing agent selected from Group comprising ethane, propane, butane, pentane; Difluoromethane (HFC-32); difluoroethane (HFC-152a); 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); and 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea). It preferably contains 5 to 95 wt .-%, in particular 10 to 70 wt .-% of 1,1,1,3,3-pentafluorobutane (HFC-365mfc).

Highly suitable compositions contain or consist of: HFC-365mfc and HFC-152a; HFC-365mfc and HFC-32; HFC-365mfc, HF-152a and CO ₂ ; HFC-365mfc, HFC-32 and CO ₂ ; HFC-365mfc, HFC-152a and butane; HFC-365mfc, HFC-32 and butane; HFC-365mfc, HFC-32 and HFC-134a; HFC-365mfc and dimethyl ether; HFC-365mfc and pentane; HFC-365mfc and propane; HFC-365mfc and ethane; HFC-365mfc, pentane and CO ₂ ; HFC-365mfc, butane and CO ₂ ; HFC-365mfc, propane and CO ₂ ; HFC-365mfc, ethane and CO ₂ .

According to a preferred embodiment, the propellant composition contains 1,1,1,3,3-pentafluorobutane (HFC-365mfc) and difluoromethane and / or 1,1-difluoroethane (HFC-152a), or it consists of these compounds. In particular, 10 to 70 wt .-% are 1,1,1,3,3-pentafluorobutane and 90 to 30% by weight of 1,1-difluoroethane or difluoromethane contain, or it consists of these components in the specified quantity ranges.

The propellant composition may also contain from 2 to 50% by weight of liquefied Contain carbon dioxide.

One embodiment of the blowing agent composition provides that, when a) HFC-365mfc and b) 1,1,1,2-tetrafluoroethane (HFC-134a); 1,1,1,3,3-pentafluoropropane (HFC-245fa); 1,1,1,3,3,3-hexafluoropropane (HFC-236fa); or 1,1,1,2,3,3,3-heptafluoropropane (HFC-227ea) but containing no CO ₂ , the propellant composition is less than 50% by weight of 1,1,1,3,3-pentafluorobutane and more than 50% by weight of 1,1,1,3,3-pentafluoropropane; Contains 1,1,1,3,3,3-hexafluoropropane or 1,1,1,2,3,3,3-heptafluoropropane or consists thereof. The same proviso also applies to this embodiment, provided that no further blowing agent from the group of low-boiling, aliphatic hydrocarbons, ethers and halogen ethers is contained.

Another object of the invention are substantially closed-cell, foamed plastics obtained by a content of the blowing agent composition according to the invention marked in the cells. In particular, it is in the essentially closed-cell foamed thermoplastics, preferably based on polystyrene, polyethylene, polypropylene, PVC or PET, in particular polystyrene.

The thermoplastic obtainable by the process according to the invention Foams have the advantage that they, compared with the use of, for example HFC-134a as a blowing agent, have improved closed cell content. For polystyrene, improved processability of the polystyrene melt is compared to the sole use of HFC-134a. The blowing agents according to the invention have sufficient solubility. The blowing agents according to the invention have no ODP and low GWP. The influence on the formation of Photosmog is extreme low.

A particular advantage of the rigid foams according to the invention is improved Properties relating to the thermal conductivity. In the cells of the foam, compared with the sole use of HFC-134a, HFC-152a and HFC-32 as Propellant, an increased residual content of propellant present.

The following examples are intended to further illustrate the invention without being limited in scope limit.

Example 1: Production of PU foams

To prepare the polyurethane foam, a polyol mixture was used as an initial component, consisting of 40 parts by weight of an ethylene diamine / propylene oxide polyether (OH number 480), 60 parts by weight of a sorbltol / glycerol / propylene oxide polyether (OHZ 490), 1 part by weight foam stabilizer (type DC 193 from Dow Corning Corp.) and 1.5 parts by weight of dimethylcyclohexylamine used. Diphenylmethane diisocyanate was used as the isocyanate component in an increased by 10 wt .-% stoichiometric amount.

a) Verwendung von HFC-365mfc/152a Erfindungsgemäß wurde eine Treibmittelzusammensetzung in einer Menge von 30 Gewichtsteilen, bezogen auf Polyolkomponente, eingesetzt. Erfindungsgemäß bestand die Treibmittelzusammensetzung aus 70 Gewichtsteilen HFC-365mfc und 30 Gewichtsteilen HFC-152a. Zusätzlich wurde 1 Gewichtsteil Wasser als chemisches Treibmittel mit verwendet. Mit der erfindungsgemäßen Treibmittelzusammensetzung wurde ein PUR-Hartschaumstoff mit einer feinzelligen Struktur und einer Dichte von ca. 32 kg/m³ mit geringer Schrumpfung hergestellt.

b) Verwendung von HFC-365mfc/32 Erfindungsgemäß wurde eine Treibmittelzusammensetzung in einer Menge von 30 Gewichtsteilen, bezogen auf Polyolkomponente, eingesetzt. Erfindungsgemäß bestand die Treibmittelzusammensetzung aus 80 Gewichtsteilen HFC-365mfc und 20 Gewichtsteilen HFC-32. Zusätzlich wurde 1 Gewichtsteil Wasser als chemisches Treibmittel mit verwendet. Mit dieser erfindungsgemäßen Treibmittelzusammensetzung wurde ein PUR-Hartschaumstoff mit einer feinzelligen Struktur und einer Dichte von ca. 28 kg/m³ mit geringer Schrumpfung hergestellt.

c) Verwendung von HFC-365mfc/152a/CO₂ Erfindungsgemäß wurde eine Treibmittelzusammensetzung in einer Menge von 22 Gewichtsteilen, bezogen auf Polyolkomponente, eingesetzt. Erfindungsgemäß bestand die Treibmittelzusammensetzung aus 70 Gewichtsteilen HFC-365mfc und 30 Gewichtsteilen HFC-152a. Zusätzlich zur erfindungsgemäßen Treibmittelzusammensetzung wurde gemäß - DE 44 39 082 - 8 Gewichtsteile verflüssigtes Kohlendioxid mit verwendet. Ferner wurde 1 Gewichtsteil Wasser als chemisches Treibmittel mit verwendet.Mit der erfindungsgemäßen Treibmittelzusammensetzung wurde ein PUR-Hartschaumstoff mit einer feinzelligen Struktur und einer Dichte von ca. 26 kg/m³ mit geringer Schrumpfung hergestellt.

The PUR foams were produced on a low-pressure system with a discharge capacity of approx. 8 kg / min, with which a dosage of 3 components is possible. The mixing unit used was a static mixer.

a) Use of HFC-365mfc / 152a According to the invention, a blowing agent composition was used in an amount of 30 parts by weight, based on the polyol component. According to the invention, the propellant composition consisted of 70 parts by weight HFC-365mfc and 30 parts by weight HFC-152a. In addition, 1 part by weight of water was used as the chemical blowing agent. With the blowing agent composition according to the invention, a rigid polyurethane foam having a fine-cell structure and a density of about 32 kg / m ³ with low shrinkage was prepared.

b) Use of HFC-365mfc / 32 According to the invention, a blowing agent composition was used in an amount of 30 parts by weight, based on polyol component. According to the invention, the propellant composition consisted of 80 parts by weight HFC-365mfc and 20 parts by weight HFC-32. In addition, 1 part by weight of water was used as the chemical blowing agent. With this inventive blowing agent composition, a rigid polyurethane foam with a fine-cell structure and a density of about 28 kg / m ³ with low shrinkage was prepared.

c) Use of HFC-365mfc / 152a / CO ₂ According to the invention, a blowing agent composition was used in an amount of 22 parts by weight, based on polyol component. According to the invention, the propellant composition consisted of 70 parts by weight HFC-365mfc and 30 parts by weight HFC-152a. In addition to the blowing agent composition according to the invention, according to DE-44 39 082 8 parts by weight of liquefied carbon dioxide were used. Further, 1 part by weight of water was used as the chemical blowing agent. The foaming agent composition of the present invention was prepared into a PUR rigid foam having a fine cell structure and a density of about 26 kg / m ³ with little shrinkage.

Example 2: Production of a polystyrene foam

a) Use of HFC-365mfc / 152a 200 kg of polystyrene (melt index 3.0-110) were mixed with 2 kg of talc as nucleating agent and this mixture was metered into a conventional extruder plant and melted. In the molten zone of the extruder about 8 wt .-% of a blowing agent according to the invention, based on the polystyrene, were metered into the polystyrene melt via an injection nozzle. The blowing agent mixture according to the invention contained 30% by weight of HFC-365mfc and 70% by weight of HFC-152a. In the mixing zone, the polystyrene melt was mixed homogeneously with the blowing agent composition according to the invention and then the resulting mixture was extruded through a die. This gave a closed-cell foam of uniform, fine-celled Struktur.Es both polystyrene foam sheets and polystyrene foam sheets were prepared according to the invention. A polystyrene foam sheet produced according to the invention had a density of 38 kg / m ³ , a polystyrene foam sheet produced according to the invention a density of 35 kg / m ³ .

b) Use of HFC-365mfc / 32 As described in example 2a), about 6% by weight of a blowing agent according to the invention, based on polystyrene, was metered into a polystyrene melt. The propellant composition of the present invention contained 30 wt% HFC-365mfc and 70 wt% HFC-32. A polystyrene film produced according to the invention had a density of 42 kg / m ³ , a polystyrene foam sheet produced according to the invention had a density of 39 kg / m ³ .

c) Use of HFC-365mfc / 134a / 152a As described in example 2a), about 8.5% by weight of a blowing agent according to the invention, based on polystyrene, was metered into a polystyrene melt. The propellant composition of the present invention contained 30 parts by weight of HFC-365mfc, 14 parts by weight of HFC-134a and 56 parts by weight of HFC-152a. A polystyrene film prepared according to the present invention had a density of 40 kg / m ³ , and a polystyrene foam sheet of the present invention had a density of 38 kg / m ³ ,

d) Use of HFC-365mfc / 152a / CO ₂ As described in example 2a), about 5.5% by weight of a blowing agent according to the invention, based on polystyrene, was metered into a polystyrene melt. The blowing agent composition of the present invention contained 30 parts by weight of HFC-365mfc, 70 parts by weight of HFC-152a. In addition to the blowing agent composition according to the invention, 8 parts by weight of liquefied carbon dioxide were used according to DE 44 39 082. A polystyrene film produced according to the invention had a density of 36 kg / m ³ and a polystyrene foam sheet produced according to the invention had a density of 33 kg / m ³ .

Example 3: Production of a polyethylene foam

a) Use of HFC-365mfc / 152a 200 kg of polyethylene (melt index 3.5-150) were extruded under conditions similar to those described in Example 2 for polystyrene. About 9 parts by weight of a blowing agent mixture, based on polyethylene, were metered in. According to the invention, a blowing agent composition of 30 parts by weight of HFC-365mfc and 70 parts by weight of HFC-152a was used. There was obtained a fine cell polyethylene foam with low shrinkage. The polyethylene foam tube produced according to the invention had a density of 38 kg / m ³ .

Claims (10)

Propellant composition containing or consisting of a) <50% by weight HFC 365mfc and b)> 50 wt% HFC 245fa. Propellant composition according to claim 1, characterized in that it contains or consists of 1 to <50% by weight of HFC 365 mfc and 99 to> 50% by weight of HFC 245 fa. Propellant composition according to claim 1, characterized in that it contains or consists of 5 to <50% by weight of HFC 365 mfc and 95 to> 50% by weight of HFC 245fa. Propellant composition according to claim 1, characterized in that it contains or consists of 10 to <50% by weight of HFC 365mfc and 90 to> 50% by weight of HFC 245fa. Propellant composition according to claim 1, characterized in that it contains or consists of 30 to <50% by weight of HFC 365mfc and 70 to> 50% by weight of HFC 245fa. Propellant composition according to any one of Claims 1 to 5, characterized in that it contains from 2 to 50% by weight of liquefied CO ₂ . Propellant composition according to one of claims 1 to 6, characterized in that it contains up to 30 wt .-% auxiliaries and additives such as plasticizers or flame retardants. Use of a blowing agent composition according to claims 1 to 7 for Production of polyurethane foams and foamed thermoplastics. Use according to claim 8, characterized in that is used as thermoplastic polystyrene, polyethylene, polypropylene, polyvinyl chloride or polyethylene terephthalate. Use according to claim 8 for the production of polyurethane foams.